PCI: expose function reset capability in sysfs
Some devices allow an individual function to be reset without affecting
other functions in the same device: that's what pci_reset_function does.
For devices that have this support, expose reset attribite in sysfs.
This is useful e.g. for virtualization, where a qemu userspace
process wants to reset the device when the guest is reset,
to emulate machine reboot as closely as possible.
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7b70312..7d55039 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2262,6 +2262,22 @@
EXPORT_SYMBOL_GPL(__pci_reset_function);
/**
+ * pci_probe_reset_function - check whether the device can be safely reset
+ * @dev: PCI device to reset
+ *
+ * Some devices allow an individual function to be reset without affecting
+ * other functions in the same device. The PCI device must be responsive
+ * to PCI config space in order to use this function.
+ *
+ * Returns 0 if the device function can be reset or negative if the
+ * device doesn't support resetting a single function.
+ */
+int pci_probe_reset_function(struct pci_dev *dev)
+{
+ return pci_dev_reset(dev, 1);
+}
+
+/**
* pci_reset_function - quiesce and reset a PCI device function
* @dev: PCI device to reset
*